this supplement are invited contributions that were presented during the 'New Frontiers of Hydrology' workshop held in Miami (Florida, USA) in January 2012. The workshop was organized under an agreement between the National Research Council of Italy (CNR) and Princeton University with the collaboration of Florida International University (FIU), who hosted the event. This was the fifth workshop of a series promoted under the umbrella of the CNR-Princeton agreement that aims to develop scientific international collaboration for discussing and promoting the most recent and advanced research in hydrology and related fields. In particular, the agreement strongly encourages the development and discussion of multidisciplinary investigations linking hydrologic phenomena with other water-related earth processes of interest for climatic, atmospheric, geomorphologic, ecological and environmental studies. The theme of this fifth workshop was 'Soil, water, and vegetation monitoring and modelling'.Invited lecturers included international scientists from Europe (mainly Italy) and the United States. A diverse group of selected contributions was presented during the workshop, which was organized in such a way that extended talks were followed by informal discussions and question and answer sessions for each topic for understanding current issues and future research trends. Among the 15 lectures that were given during the workshop, eight were selected to be part of this supplement. The selected contribution themes include innovative Geographic Information System (GIS) procedures for identification of flood-prone areas (two papers), empirical and numerical modelling of shallow and storm flood waters (two papers), hydrometeorologic and hydrologic statistic studies on flow duration curves, rainfall thresholds and the event-based frequency analysis of antecedent moisture conditions (three papers), and one paper on water quality for environmental pollution studies.The first two papers deal with flood hazard characterization at the large scale, by means of advanced GIS techniques implementing hydrogeomorphic analyses, using the digital elevation model (DEM) as the main source of information. The paper by Massimiliano Degiorgis, Giorgio Gnecco, Silvia Gorni, Giorgio Roth, Marcello Sanguinetti and Angela Celeste Taramasso presents results from the case study of the Tanaro basin in Northern Italy, concerning the use of an innovative method for flood hazard assessment via threshold binary classifiers, with the main goal of characterizing the residual hydraulic risks that impact river networks from the main rivers to tributaries and minor channels (Degiorgis et al., 2013). The second paper, by Fernando Nardi, Chiara Biscarini, Silvia Di Francesco, Piergiorgio Manciola and Lucio Ubertini, presents the investigations conducted for floodplain identification in the Tiber river basin in central Italy by means of a DEM-based hydrogeomorphic method, which was compared to the use of standard flood maps for preliminary mapping of river valleys at t...